In recent years, contactless transmission devices in which two resonance components are closely arranged without wiring cables and the like and which perform data communication in a non-contact manner, and contactless transmission methods have attracted attention. Further, among such contactless transmission devices and contactless transmission methods, there are those that handle power as the transmission object, and contactless power feeding without a power supply cable has been attempted.
In such a situation, a dielectric contactless transmission device using dielectric material as the transmission/reception unit for a transmission object in order to improve transmission efficiency of the contactless transmission device is known (for example, see Patent Documents 1 and 2).
For example, Patent Document 1 discloses a dielectric contactless transmission device that respectively covers two resonance components (dielectric resonance components) formed of dielectric material with shielding cases each of which has an opening so that the openings face each other, and causes the openings to perform electromagnetic field coupling, thereby to realize wireless transmission of power. The dielectric resonance component described in Patent Document 1 reduces loss by covering the dielectric resonance components with the shielding cases, thereby to improve the unloaded Q value and improve power transmission efficiency.
Further, Patent Document 2 discloses a dielectric contactless transmission device in which microstrip resonance elements each of which has a ground electrode and a resonance electrode arranged on the front and back surfaces of a dielectric substrate are produced, and the two microstrip resonance elements are arranged to cause the resonance electrodes to face each other. The dielectric contactless transmission device described in Patent Document 2 sets both of the two microstrip resonance elements to have a size equal to ⅓ to ½ of the wavelength of a high frequency signal, thereby to secure favorable transmission efficiency.    Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2014-003773    Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2012-085234